Start of ship date range used to narrow search.
For FedEx, this property value is optional to be entered in a track request (when the TrackShipment is called), but recommended as limits the results to this range. If not provided, results may vary. In this case, FedEx will default to a range that may not be useful for the search. If provided, ShipDateEnd is required. Format: YYYY-MM-DD.
For UPS, this describes the start of a pickup date range used to narrow down the search, and is optional. However, this is considered in the request only if ShipDateEnd is set as well. Otherwise, it will be disregarded. Format: YYYYMMDD.
This property does not apply to USPS.